As soon as cameras and photo equipment could be reliably used outdoors, a varied and detailed record of the American landscape began to evolve, as seen in the 52 photographs here spanning 1855–1990. Many 19th-century photographers worked on government-sponsored surveys, while others helped to lure investors westward with images made along railroad routes. Photos of unspoiled national treasures by Carleton Watkins and Eadweard Muybridge influenced the federal government's efforts to create national parks, while poetic images by Ansel Adams began to be hung as art in American homes. Later photographers have recorded their impressions of both man's and nature's impact on the land, from Robert Dawson's images of polluted waterways to Larry Schwarm's almost abstract image of a prairie fire and Emmet Gowin's views of the aftermath of Mount St. Helens' 1980 eruption.